Chummer uses XML files for all of its data. These data files can be found in Chummer's data directory. While you can enter custom data for Chummer, you should not modify these core files as they are overwritten with new versions by the update process. Instead, custom data should be placed in Custom Data Files. For information on creating Custom data, please refer to the Custom Data Files page.

Below is a list of the data files that are currently used and a brief description of the data they contain. You can get more detailed information for a particular file by clicking on its name.